complete day 2 part 2

day02.go

@@ -8,7 +8,9 @@ import (
 	"strings"
 )
 
-func validgame(totalred, totalgreen, totalblue int, r io.Reader) bool {
+var replacer = strings.NewReplacer(",", " ", ";", " ")
+
+func maxgame(r io.Reader) (red, green, blue int) {
 	scanner := bufio.NewScanner(r)
 	scanner.Split(bufio.ScanWords)
 
@@ -17,26 +19,26 @@ func validgame(totalred, totalgreen, totalblue int, r io.Reader) bool {
 			break
 		}
 
-		num, _ := strconv.Atoi(scanner.Text())
+		n, _ := strconv.Atoi(scanner.Text())
 
 		scanner.Scan()
 		switch scanner.Text() {
 		case "red":
-			if num > totalred {
-				return false
+			if n > red {
+				red = n
 			}
 		case "green":
-			if num > totalgreen {
-				return false
+			if n > green {
+				green = n
 			}
 		case "blue":
-			if num > totalblue {
-				return false
+			if n > blue {
+				blue = n
 			}
 		}
 
 	}
-	return true
+	return
 }
 
 type day02 struct{}
@@ -48,14 +50,14 @@ func (d day02) solve1(r io.Reader) string {
 		totalblue  = 14
 		gameSum    = 0
 		scanner    = bufio.NewScanner(r)
-		replacer   = strings.NewReplacer(",", " ", ";", " ")
 	)
 
 	for gameN := 1; scanner.Scan(); gameN++ {
 		line := scanner.Text()
 		_, game, _ := strings.Cut(line, ": ")
 		sr := strings.NewReader(replacer.Replace(game))
-		if validgame(totalred, totalgreen, totalblue, sr) {
+		red, green, blue := maxgame(sr)
+		if red < totalred && green < totalgreen && blue < totalblue {
 			gameSum += gameN
 		}
 	}
@@ -64,5 +66,18 @@ func (d day02) solve1(r io.Reader) string {
 }
 
 func (d day02) solve2(r io.Reader) string {
-	return ""
+	var (
+		sum     = 0
+		scanner = bufio.NewScanner(r)
+	)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		_, game, _ := strings.Cut(line, ": ")
+		sr := strings.NewReader(replacer.Replace(game))
+		red, green, blue := maxgame(sr)
+		sum += (red * green * blue)
+	}
+
+	return fmt.Sprintf("%d", sum)
 }

main_test.go

@@ -37,8 +37,7 @@ func TestDay01(t *testing.T) {
 }
 
 func TestDay02(t *testing.T) {
-	ans1 := "8"
-	input1 := `Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+	input := `Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
 Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
 Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
 Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
@@ -46,10 +45,18 @@ Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green`
 
 	puzzle := day02{}
 
-	res1 := puzzle.solve1(strings.NewReader(input1))
+	ans1 := "8"
+	res1 := puzzle.solve1(strings.NewReader(input))
 	t.Logf("day 2 solution 1: %s", res1)
 	if res1 != ans1 {
 		t.Errorf("day 2 solution 1 = %s; wanted %s", res1, ans1)
 	}
 
+	ans2 := "2286"
+	res2 := puzzle.solve2(strings.NewReader(input))
+	t.Logf("day 2 solution 2: %s", res2)
+	if res2 != ans2 {
+		t.Errorf("day 2 solution 2 = %s; wanted %s", res2, ans2)
+	}
+
 }